Method of making photographically accurate prints



A ril 18, 1967 F. s. TOBEY 3,314,816

METHOD OF MAKING PHOTOGRAPHICALLY ACCURATE PRI Filed Aug. 2. 1962 NTS v Imam so as to make impractical use United States Patent 3 314,816 METHOD OF MAKIl IG PHUTOGRAPHICALLY ACCURATE PRINTS Frederic S. Tobey, Walpole, Mass, assignor to H. Brady Company, Milwaukee, Wis., a corporation of Wisconsin Filed Aug. 2, 1962, Ser. No. 214,282 1 Claim. (Cl. 117-101) This invention relates to a method for making prints with photographic accuracy and without any layer of gelatin or the like.

typically included a layer of soluble organic material, such as gelatin, and, arranged thereln to define photographic Such prints have various d1sprint or transparency, or a negative print may be made directly 'from a conventional negative photostill with photographic accuracy, well below the surface advantage that if the surface becomes illegible, as because dirty, it may be buffed off to reproduce a legible image.

Generally speaking, in my new defining relationship by said base.

If desired, said 'base or the receiving surface thereof may be made so porous that the solid particles are driven well below the surface thereof.

The base may comprise any suitable material, includ ing for example blotting plastic, for example Mylar. The organic layer may be or bond paper, glass cloth, or a 3,314,816 Patented Apr. 18, 1967 process is being practiced, starting with a conventional positive photographic print. FIG. 2 is an enlarged sectional view at an early stage in the practice thus of the process, taken at 2-2 of FIG. 1.

in the figures for clarity).

Preferred embodiments of the new method of the invention will now be set forth. In all the follow Example I The gelatin layer of a conventional photographic print (1n which a developed and fixed photographic emulsion, constituting particles of silver carried in photographic arra ngement in a layer of hardened gelatin, was integral print for ten minutes at room temperature in a dilute solutron of sodium hydroxide. The print was then placed in which was ten inches in diameter) for in the presence of the Rotation was radially outwardly and been deposited and held on the paper.

Example 2 A conventional photographic transparency and a conventlonal solution of Gelatinase No 3 wer I 1: p p against the perforated cylindrical ten-inch diameter baskm 14 of the centrifuge shown in FIG. 1, which was rotated about the axis of the cylindrical surface of basket 14 to impose a centrifugal force of 15,000 times gravity, while there was simultaneously introduced warm Gelatinase No. 3 solution through pipe 16 for ten minutes. The centrifuge was then stopped and the film with which the gelatin has been integral was removed. The blotting paper, now bearing the silver particles, was then centrifuged for five more minutes while passing through further solution to dissolve any remaining bits of gelatin, and five more minutes with wash water, at all times at 15,000 times gravity. A print of photographic accuracy on the blotting paper resulted, silver particles appearing well below the surface thereof in relative densities preserving the image of the original transparency.

Example 3 The procedure set forth in Example 2 was repeated, except that glass cloth was used instead of blotting paper for a base. A gelatin-free print of photographic accuracy on glass cloth was obtained, which remained sharp and clear even after heating for one hour at 500 F.

Example 4 The gelatin layer of an ordinary photographic transparency, carrying'silver particles defining a photographic image and constituting together therewith a developed and .fixed photographic emulsion, was softened with a solution of Gelatinase No. 3. The surface of the softened gelatin layer was placed against the roughened surface of Mylar film roughened by vapor-blasting with finely divided grit to a finely frosted appearance, the other surface of the Mylar film being placed against a cylindrical imperforate centrifuge basket. As in the other examples above set forth, all portions of the gelatin or organic layer surface were equidistant from the axis of rotation of the basket, as were all portions of the support surface in contact with the gelatin surface. The basket was then rotated for ten minutes in the presence of the solvent solution, to produce a force of 5,000 times gravity throughout the gelatin layer and against the roughened surface of the Mylar support. A print on Mylar, of photographic accuracy, resulted.

Example 5 A photographic print with a 7 x 78" image was placed on the flat bottom of a bottle, which was mounted on an arm parallel to the centerline of the bottle and perpendicular to its bottom. Softening, destruction of the gelatin layer and washing were under the conditions set forth for Example 1, using a batch approach as there. Rotation was on said arm, the flat bottom of the bottle being 10 /2 inches from the axis of rotation and generally perpendicular to the radius extending from said axis through the center of said bottom. A print of photographic accuracy, free from gelatin, resulted.

Other embodiments within the invention and appended claim will occur to those skilled in the art, the embodiments of the above examples being exemplary only. My new process may desirably be used in making up labels, for example, with such high definition that they may be read only by means of a magnifying glass and with great heat resistance, or in the making up of prints of photographic accuracy on cloth, blotters, solid objects such as ashtrays, or other materials, which may be chosen for such characteristics as to flexibility, durability, heat resistance, porosity, and so on, as seem desirable for the end use required. Coatings, heat-resistant (such as 'of silicones) or otherwise, may be used on the receiving surface of the base, either before or after depositing thereon the solid particles defining thereon an image, to increase adhesion, protect against dirt or abrasion, or give a modified appearance.

I claim:

The method of manufacturing a print which comprises the steps of supporting against the cylindrical wall of a centrifuge basket a base and supporting against the base and inwardly thereof a layer of hydrophilic colloid carrying dispersed therein silver particles defining a photographic image, rotating said basket to give said base and said layer the same angular velocity, dissolving said hydrophilic colloid to release said silver particles therefrom, and moving said silver particles radially onto said base for retention thereon to give an image reproducing with photographic accuracy the image already referred to.

References Cited by the Examiner UNITED STATES PATENTS 2,119,309 5/1938 Batchelor 117-10l X 2,339,131 1/1944 Anderson l1763 X 2,339,178 1/1944 Lemrners ll7--63 X 3,097,112 7/1963 Schutze et al. 1l7l0l X 3,212,929 10/1965 Pliskin et al 117-401 X ALFRED L. LEAVI'IT, Primary Examiner. RALPH S. KENDALL, Examiner. 

